Connector having a pair of printed circuits and facing sets of contact beams

ABSTRACT

A connector assembly includes a male connector and a female connector. The female connector includes two printed circuit assembly portions (PCAPs). Each PCAP includes a printed circuit having a ground plane and a plurality of conductors. A plurality of contact beams are attached to the conductors so that the PCAP structure resembles a comb. The two PCAPs are disposed in an insulative portion of the female connector such that the two rows of contact beams face one another. The male connector also includes two PCAPs. The PCAPs in the male connector do not have contact beams but rather have exposed conductors. When the male and female connectors are mated, the contact beams on the female connector make contact with the exposed conductors on the PCAPs in the male connector. The structure of the PCAPs in the assembly are microstrip-like and the characteristic impedance through the mated connectors is substantially uniform.

TECHNICAL FIELD

The present invention relates generally to high-speed connectors.

BACKGROUND INFORMATION

FIG. 1 (Prior Art) is a perspective view of stacked connector assembly1. Stacked connector assembly 1 includes a male surface mount connector2 and a female surface mount connector 3.

FIG. 2 (Prior Art) is cross-sectional view of male connector 2 andfemale connector 3 of FIG. 1. The cross-section of the male connector 2reveals a pair of L-shaped metal pieces 4 and 5, referred to here aspins. These pins are inserted into holes in an insulative portion 6 sothat the pins stay in place as illustrated. The upper portion of pin 4is a solder tail 7. The upper portion of pin 5 is a solder tail 8. Thesolder tails 7 and 8 are soldered to corresponding conductors of aprinted circuit board 9 so that male connector 2 is physically fixed tothe first printed circuit board.

The cross-section of the female connector 3 reveals a pair of metalinserts 10 and 11. Metal insert 10 has a solder tail portion 12 and aflexing contact portion 13. Metal insert 11 has a solder tail portion 14and a flexing contact portion 15. The inserts 10 and 11 are insertedinto holes in an insulative portion 16 so that the inserts stay in placeas illustrated. The solder tail portions 12 and 14 are for soldering tocorresponding conductors on the top of a second printed circuit board17.

FIG. 3 (Prior Art) is a cross-sectional view of male connector 2 andfemale connector 3 of FIG. 2 when the two connectors are mated. Contactportion 13 presses inward to the right on pin 4 thereby establishing afirst conductive path through the connector assembly between solder tail7 and solder tail 12. Similarly, contact portion 15 pressed inward onpin 5 to the left thereby establishing a second conductive path throughthe connector assembly between solder tail 8 and solder tail 14.

FIG. 4 (Prior Art) is a simplified diagram representing the orientationof the conductive portions within the connector assembly. The diagram isof a cross-section taken through the two connectors 2 and 3 abouthalfway between, and parallel to, printed circuit boards 9 and 17. Thedark rectangles are very simplified representations of cross sections ofconductive portions.

FIG. 5 (Prior Art) is a perspective view of an improved connectorassembly 18 that includes a male connector 19 and a female connector 20.Note that every second one of the solder tails in the two rows of soldertails on the upper surface of male connector 19 are electrically coupledtogether. Reference numeral 21 illustrates one such pair of solder tailsthat is formed as a bar or strip.

FIG. 6 (Prior Art) is a cross-sectional diagram of the connectorassembly 18 of FIG. 5. The cross-section of FIG. 6 is taken through theconnector assembly at the location of pair 21. Rather than there beingtwo separate pins in the male connector 19 as in the case of FIG. 2,there is a single piece 22 of stamped metal that is inserted intoinsulative portion 23. Metal piece 22 has two solder tails 24 and 25that are usable to solder the male connector 19 to a first printedcircuit board 26. Rather than there being two separate metal inserts inthe female connector 20 as in the case of FIG. 2, there is a singlepiece 27 of stamped metal that has two contact portions. Piece 27 hastwo solder tails 28 and 29 that are usable to solder female connector 20to a second printed circuit board 30.

FIG. 7 (Prior Art) is a view taken at the same sectional line as FIG. 6,except that FIG. 7 shows the connector assembly structure when the twoconnectors 19 and 20 are mated. Note that the flexing contact portions31 and 32 press inward and make electrical contact with metal piece 22.Note that a large portion of the cross-sectional area of the connectorassembly in FIG. 7 is metal that is electrically coupled together.

FIG. 8 (Prior Art) is a cross-sectional view through the connectorassembly 18, but the cross-section is taken through a pair of soldertails that are not joined together. The cross-section of FIG. 8 appearsmuch like the cross-section of FIG. 2, except that the press fitextension portions on metal inserts 10 and 11 have been eliminated.

FIG. 9 (Prior Art) is a cross-sectional view taken in same plane as thecross-sectional view of FIG. 8, except that male connector 19 and femaleconnector 20 are shown in the mated position. Contact portion 33 pressesinward to the right on pin 34 thereby establishing a first conductivepath through the connector assembly between solder tail 35 and soldertail 36. Similarly, contact portion 37 pressed inward to the left on pin38 thereby establishing a second conductive path through the connectorassembly between solder tail 39 and solder tail 40.

FIG. 10 (Prior Art) is a simplified diagram representing the orientationof the conductive portions within the connector assembly of FIG. 5. Thediagram is of a cross-section taken through the two connectors 19 and 20about halfway between, and parallel to, printed circuit boards 26 and30. The dark rectangles represent cross sections of conductors. Thelonger rectangle 41 represents the conductive portions illustrated inFIGS. 6 and 7. These conductive portions are coupled to ground potentialand form what approximates a ground plane that extends in the verticaldimension in FIG. 10. The smaller rectangles 42 and 43 represent theconductive portions in the plane of FIGS. 8 and 9. Rectangle 43represents contact portion 37 and pin 38, whereas rectangle 43represents contact portion 33 and pin 34. The conductors represented byrectangles 42 and 43 are used to conduct differential signals. Note thatthe topology of the ground portions and signal portions of FIG. 10 comescloser to a microstrip topology in that pairs of signal conductors aredisposed side by side with respect to one another, and in that the pairof signal conductors are disposed over a ground plane. Because thetopology of FIG. 10 is closer to that of a microstrip topology than isthe topology of FIG. 4, the connector assembly of FIG. 5 can handlehigher frequency signals that the connector assembly of FIG. 1. Oneexample of a connector assembly that has a form similar to the form ofthe connector assembly of FIG. 5 is the so-called “Micro GigaCN stackingconnector” from Fujitsu, model number FCN-260. The FCN-260 connectorassembly is reported to be able to handle signals up to approximatelythree gigabits per second. A connector assembly is desired that canhandle higher frequency signals.

SUMMARY

A connector assembly includes a male surface mount connector and afemale surface mount connector. The female connector includes twoprinted circuit assembly portions (PCAPs). Each PCAP includes a printedcircuit portion having a ground plane on one side and a plurality ofstrip-shaped conductors on the other side. A plurality of contact beamportions are attached to the strip-shaped conductors so that the PCAPstructure resembles a comb having a ground plane in the backbone portionof the comb. Every third contact beam of a PCAP is coupled through theprinted circuit of the PCAP to the ground plane. The pairs of contactbeams between the grounded contact beams are used to communicatedifferential signals between the male and female connectors. The PCAPsare disposed in an insulative portion of the female connector such thatthe two rows of contact beams of the two PCAPs face one another.

The male connector also includes two PCAPs and an insulating portionthat holds the two PCAPs. Each PCAP in the male connector has a groundplane on one side and a plurality of exposed conductors on the otherside. Unlike the PCAPs in the female connector, the PCAPs in the maleconnector do not have contact beams. The PCAPs in the male connector aredisposed such that the ground plane sides of the PCAPs are back-to-backand such that the exposed conductors are facing outwardly and away fromone another.

When the male and female connectors are mated, the contact beams on thefemale connector make electrical contact with the exposed conductors onthe PCAPs in the male connector. Electrical signals are communicatedfrom a surface mount attachment feature (for example, a solder tail) onone of the connectors, through a contact beam to the other connector,and to a surface mount attachment feature (for example, a solder tail)on the other connector. Every third surface mount attachment feature andcontact beam is coupled to ground potential and to ground planes in thefour PCAPs of the connector assembly. Accordingly, the groundedconductors of the connector assembly form a set of shielded structuresthat represent tubes through which pairs of signal paths run from oneconnector to the other connector. When the connector assembly isconsidered in cross-section, the conductors of the assembly have amicrostrip-like geometry of ground plane and pairs of signal conductors.The geometries, materials and electrical properties of the PCAPs in themale and female connectors are microstrip-like and may closelyapproximate the geometries, materials and electrical properties in theprinted circuit boards from which the electrical original, and to whichthe electrical signals are conducted. The printed circuits of the PCAPsmay be printed circuit boards.

In one embodiment, the characteristic impedance of a signal path throughthe mated connector assembly varies by less than plus or minus tenpercent. At a signal rate of 22 gigahertz through the signal path, theinsertion loss is better than −3 dB (the signal propagation down thesignal path has degraded by less than −3 dB), and the return loss isbetter than −10 dB (the magnitude of reflections is less than −10 dB).

Other embodiments and advantages are described in the detaileddescription below. This summary does not purport to define theinvention. The invention is defined by the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, where like numerals indicate like components,illustrate embodiments of the invention.

FIGS. 1–3 (Prior Art) are views of a conventional stacked surface mountconnector.

FIG. 4 (Prior Art) is a simplified diagram that represents thegeometries of conductors within the connector assembly of FIGS. 1–3.

FIGS. 5–9 (Prior Art) are views of an improved conventional stackedsurface mount connector.

FIG. 10 (Prior Art) is a simplified diagram that represents thegeometries of conductors within the connector assembly of FIGS. 5–9.

FIG. 11 is a perspective view of a novel connector assembly inaccordance with the present invention.

FIG. 12 is a perspective view of the female connector of the connectorassembly of FIG. 11.

FIG. 13 is a cross-sectional view taken along line A—A in FIG. 12.

FIG. 14 is an exploded view of the female connector of FIG. 11.

FIG. 15 is a diagram of one of the printed circuit assembly portions(PCAPs) of the female connector of FIG. 11.

FIG. 16 is an expanded cross-sectional view taken along line B—B in FIG.15.

FIG. 17 is an exploded view of the PCAP of FIG. 16. The PCAP is made byfixing the printed circuit to the stiffener using an adhesive. Acomb-shaped structure is stamped out of rigid metal to form a set ofcontact beam portions that extend from a backbone of the comb structure.The ends of the contact beams are then bent to have the desired shape ofthe contact beams as illustrated in FIG. 16. The formed comb-shapedstructure is then soldered or brazed to exposed conductors on theexposed surface of the printed circuit. The backbone portion of thecomb-shaped structure is then cut off, leaving short ends of the contactbeams. These short ends are then bent to form solder tails of the shapeillustrated in FIG. 16. After this process, each contact structure is aseparate strip of stamped metal that is fixed to the printed circuit.

FIG. 18 is a more detailed diagram of a portion of the printed circuitof the PCAP of FIG. 17.

FIG. 19 is a more detailed diagram of a portion of the printed circuitof FIG. 18.

FIG. 20 is a simplified cross-sectional diagram that illustrates themicrostrip-like structure of the conductors within the printed circuitof the PCAP of FIG. 18.

FIG. 21 is a perspective view of a portion of the printed circuit ofFIG. 18 with the dielectric and solder mask layers not shown.

FIG. 22 is a cross-sectional diagram of the female connector of FIG. 11.

FIG. 23 is an expanded view of a portion of the female connector of FIG.22.

FIG. 24 is a perspective view of the male connector of FIG. 11.

FIG. 25 is a cross-sectional diagram taken along line C—C in FIG. 24.

FIG. 26 is an exploded view of the male connector of FIG. 24.

FIG. 27 is a view of one of the PCAPs of the male connector of FIG. 24.

FIG. 28 is an expanded cross-sectional view taken along line D—D in FIG.27.

FIG. 29 is an exploded view of one of the PCAPs of the male connector ofFIG. 29.

FIG. 30 is an expanded view of a portion of the printed circuit withinthe PCAP of FIG. 29.

FIG. 31 is an expanded view of a portion of the printed circuit of FIG.30.

FIG. 32 is a perspective view of a portion of the printed circuit ofFIG. 31 with the dielectric layer and the solder mask layers not shown.

FIG. 33 is a cross-sectional diagram of the male connector of FIG. 24.

FIG. 34 is an expanded view of a portion of the male connector of FIG.33.

FIG. 35 illustrates the male and female connectors of the connectorassembly of FIG. 11 before mating.

FIG. 36 illustrates the male and female connectors of the connectorassembly of FIG. 11 after mating.

FIG. 37 is a simplified cross-sectional diagram that illustrates a partof a signal path through the connector assembly of FIG. 11. The signalpath illustrated is one of two signal paths that is used to conduct asingle differential signal.

FIG. 38 is a simplified cross-sectional diagram that illustrates a setof inter-coupled and grounded conductors that forms a sort of groundedshield in the plane of the diagram. There is one such grounded shieldthat separates every successive pair of signal conductor structures ofthe type illustrated in FIG. 37. The ground planes of the groundedstructure of FIG. 38 extend into the plane of the diagram.

FIG. 39 is a graph illustrating electrical characteristics (insertionloss and return loss) of the novel connector assembly of FIG. 11.

FIG. 40 is a perspective view of a “vertical mating” embodiment of thenovel connector assembly.

FIG. 41 is a cross-sectional view of the vertical mating embodiment ofFIG. 40.

FIG. 42 is a diagram of the stacking connector assembly of FIGS. 11–39.

FIG. 43 is a diagram of the vertical mating connector assembly of FIGS.40–41.

FIG. 44 is a diagram of a horizontal mating embodiment of the novelconnector assembly.

FIG. 45 is a diagram of an extended parallel mating structure inaccordance with the novel connector assembly.

DETAILED DESCRIPTION

Reference will now be made in detail to some embodiments of theinvention, examples of which are illustrated in the accompanyingdrawings.

FIG. 11 is a perspective view of a novel connector assembly 100.Connector assembly 100 includes a male connector 101 and a femaleconnector 102. Male connector 101 is illustrated physically connected toa first printed circuit board 103. Female connector 102 is illustratedphysically connected to a second printed circuit board 103A. Theconnectors 101 and 102 of the connector assembly 100 are usable tocouple electrical conductors (for example, signal traces) in firstprinted circuit board 103, through the connector assembly (when mated),to electrical conductors (for example, signal traces) in second printedcircuit board 103A.

FIG. 12 is a more detailed perspective view of female connector 102.

FIG. 13 is a detailed cross-sectional diagram taken along sectional lineA—A in FIG. 12. Female connector 102 includes an insulative housingportion 103, a first printed circuit assembly portion (PCAP) 104, and asecond PCAP 105. Insulative portion 103 may, for example, be made ofLiquid Crystal Polymer (LCP) material that has a dielectric constant ofapproximately 3.5 to 4.0 and exhibits small mold shrinkagecharacteristics. First PCAP 104 includes a first printed circuit (PC)106, a stiffener 107, and a plurality of contact beam portions. Thecontact beam portions are physically connected to first PC 106 so thatthe contact beam portions are all disposed parallel to one another asillustrated. Reference numeral 108 indicates one such contact beamportion. The upper portion of contact beam portion 108 is a flexiblecontact beam 109 that is bent to have the form illustrated. The lowerportion of contact beam portion 108 is a surface mount attachmentfeature 110 (in this case, a solder tail).

Second PCAP 105 has an identical construction to the construction ofPCAP 104. The first PCAP 104 and the second PCAP 105 are disposed in andare coupled to insulative housing portion 103 such that the contact beamportions on the respective first and second PCAPs 104 and 105 face oneanother as illustrated. Second PCAP 105 includes a second printedcircuit (PC) 111, a stiffener 112, and a plurality of contact beamportions. The contact beam portions are physically connected to secondPC 111 so that the contact beam portions are all disposed parallel toone another as illustrated. Reference numeral 113 indicates one suchcontact beam portion. The upper portion of contact beam portion 113 is aflexible contact beam 114. The lower portion of contact beam portion 113is a surface mount attachment feature 115 (in this case, a solder tail).When the first and second PCAPs 104 and 105 are disposed in insulativehousing portion 103, a male connector receiving slot (MCRS) 116 isformed between the facing contact beam portions of the PCAP 104 and thecontact beam portions of the PCAP 105. As illustrated in FIG. 12,insulative housing portion 103 includes polarization guide structures117–120 that prevent the male connector 101 from being inserted into thefemale connector 102 unless the male and female connectors are orientedwith respect to one another in a proper end-to-end orientation. Peg-likeextension features 121 and 122 on the bottom of insulative housing 103stick down into corresponding receiving holes in printed circuit board103A to align the female connector 102 on the printed circuit board 103Aand to provide mechanical strength.

FIG. 14 is an expanded exploded view of female connector 102. The firstand second PCAPs 104 and 105 are shown underneath an outside ofinsulative housing portion 103. During assembly, each PCAP is insertedup in direction Y into a corresponding receiving slit in the bottom ofinsulative housing portion 103.

FIG. 15 is an expanded view of second PCAP 105. The side edges (on thesmall sides of the rectangle) of stiffener 112 include downward pointinganchoring barbs. Two such barbs 123 and 124 are illustrated in FIG. 15.During connector assembly, the PCAP 105 is pushed up into the receivingslit until the barbs on the stiffener 112 snap into correspondingretaining openings in the sides of the receiving slit. The bards holdthe PCAP 105 in place.

FIG. 16 is an expanded cross-sectional view taken along sectional lineB—B in FIG. 15. Second printed circuit 111 includes a conductive groundplane 125 that is on the surface of printed circuit 111 that facesstiffener 112. A layer of insulative solder mask separates ground plane125 from stiffener 112. The stiffener 112 may, for example, be fixed byadhesive to second printed circuit 111. Second printed circuit 111 alsoincludes an insulative substrate dielectric material 126 such as afiberglass epoxy material commonly used to make printed circuit boards.Second printed circuit 111 also includes a plurality of strip-shapedconductors that are disposed on the surface of printed circuit 111 thatfaces the contact beam portions. Reference numeral 127 indicates onesuch strip-shaped conductor in the cross-sectional view of FIG. 16. Eachcontact beam portion is physically and electrically coupled to acorresponding one of the strip-shaped conductors on the printed circuit.The contact beam portions can, for example, be soldered to or brazed tothe strip-shaped conductors. Contact beams portion 113 in thecross-sectional view of FIG. 16 is a ground contact beam portion asopposed to a contact beam portion that is used to communicate signals.The strip-shaped conductor 127 to which contact beam portion 113 isattached is coupled through printed circuit 111 by conductive throughholes 128 and 128A to ground plane 125. Although not illustrated in FIG.16, first PCAP 104 has an identical construction to the construction ofsecond PCAP 105 illustrated in FIG. 16.

FIG. 17 is an exploded view of second PCAP 105 showing metal stiffener112, second printed circuit 111, and the plurality of contact beamportions 129 that are connected to the second printed circuit 111. Notethat the face of second printed circuit 111 to which the contact beamportions 129 are connected has a solder mask layer that covers the faceillustrated in FIG. 17, but for a longitudinal rectangular window 131 ofthe printed circuit that is not covered with solder mask. Where thecontact beam portions 129 are soldered to or brazed to the strip-shapedconductors on printed circuit 111, the sold or brazed connection is madein the window area where no solder mask layer 130 is present.

FIG. 18 is an expanded cross-sectional view of second printed circuit111. Every third strip-shaped conductor is a ground conductor that islonger than the intervening pair of shorter strip-shaped conductors usedto communicate signals. Reference numerals 132 and 133 indicate two suchlonger strip-shaped ground conductors. The pair of shorter strip-shapedconductors 134 and 135 are used to conduct differential signals whereasthe longer strip-shaped conductors 132 and 133 are ground conductors.The cross-sectional view of FIG. 18 illustrates the exposed portions ofthe strip-shaped conductors within window 131 to which the contact beamportions are attached. The conductive through holes that electricallycouple the longer strip-shaped ground conductors 132 and 133 to theground plane 125 on the opposite side of second printed circuit 111 areindicated by reference numerals 136–139.

FIG. 19 is an expanded view of the conductive through hole 136 in thebox 140A of FIG. 18. Conductive through hole 136 electrically coupleslong strip-shaped conductor 132 on one side of second printed circuit111 to ground plane 125 on the opposite side of second printed circuit111. The ground plane 125 is covered by a layer of solder mask 140 thatinsulates ground plane 125 from metal stiffener 112. Metal stiffener 112is, in one embodiment, a fairly rigid and strong piece of metal that isstamped out of a sheet of metal. Stiffener 112 is not grounded in thisembodiment but rather is electrical isolated (floating).

FIG. 20 is a simplified cross-sectional view of the structure of secondprinted circuit 111. The strip-shaped signal conductors 134 and 135 aredisposed side-by-side between a pair of longer strip-shaped groundconductors 133 and 132. A ground plane 125 underlies the entirestructure. The structure therefore has a topology that resembles amicrostrip design. In one embodiment, the dimensions and spacings andmaterials of the conductors 125, 132–135 and dielectric material 126 aresimilar to the conductor and dielectric dimensions and spacings withinprinted circuit board 103A. Because the geometries and electricproperties of the materials through which an electrical signal passesfrom a trace in printed circuit board 103A and into and through aconductor in female connector 102 are similar, the characteristicimpedance along the entire signal path is made to vary by less than plusor minus ten percent. This uniformity in characteristic impedance isdesirable and minimizes unwanted reflections.

FIG. 21 is a perspective view of a portion of second printed circuit111. The dielectric material and solder mask layers are not illustratedin order to make the strip-shaped conductors, the conductive throughholes, and the ground plane less obscured.

FIG. 22 is a cross-sectional diagram of female connector 102 taken alongline A—A of FIG. 12. Volume 116 is the male connector receiving slot(MCRS) into which a portion of male connector 101 fits when maleconnector 101 is mated to female connector 102.

FIG. 23 is an expanded view of box 141 of FIG. 22. In the example ofFIG. 23, the surface mount attachment feature 115 is a solder tailextension of contact beam portion 113. The detail of second printedcircuit 111 and stiffener 112 is illustrated. To realize the microstripdesign topology, contact beam portion 113 is electrically coupled byconductive through hole 128 to ground plane 125. Volume 142 betweencontact beam portion 113 and the exposed portion of ground conductor 127(the portion not covered by solder mask) is filled with solder orbrazing material that connects the contact beam portion 113 tostrip-shaped conductor 127.

FIG. 24 is a perspective view of male connector 101. Like femaleconnector 102, male connector 101 has surface mount attachmentstructures (in this case, solder tails) by which the connector isconnected to printed circuit board 103. The surface mount attachmentfeatures appear as two rows 143 and 144. Peg-like extension features 145and 146 on insulative portion 147 stick up into corresponding receivingholes in printed circuit board 103 to align male connector 101 onprinted circuit board 103 and to provide mechanical strength.

FIG. 25 is an expanded cross-sectional perspective view of maleconnector 101 taken along sectional line C—C in FIG. 24. Male connector101 includes an insulative portion 147, a first printed circuit assemblyportion (PCAP) 148, and a second PCAP 149. First PCAP 148 includes afist printed circuit 150, a plurality of surface mount attachmentfeatures (in this case, solder tails), and a stiffener 151. One of thesolder tails is indicated by reference numeral 152. The second PCAP 149is of identical construction to the first PCAP 148. The second PCAP 149includes a second printed circuit 153, a plurality of surface mountattachment features (in this case, solder tails), and a stiffener 154.One of the solder tails is indicated by reference numeral 155. The firstand second PCAPs 148 and 149 are disposed in back to back relation asillustrated such that the stiffener portions of the PCAPs 148 and 149face one another, and such that the solder tails of the two PCAPs 148and 149 flare outwardly and extend away from one another.

FIG. 26 is an exploded view of male connector 101. The first and secondPCAPs 148 and 149 are shown outside of insulative portion 147. Likeinsulative portion 103, insulative portion 147 is made of Liquid CrystalPolymer (LCP) material. Insulative portion 147 has polarization guidestructures 156 and 157 (two other polarization guide structures are onother hidden side of insulative portion 147) that prevent the maleconnector 101 from being inserted into the female connector 102 unlessthe male and female connectors are oriented with respect to one anotherin a proper end-to-end orientation. When male connector 101 isassembled, the first and second PCAPs 148 and 149 are slid down indirection Z into corresponding receiving slits in insulative housing147. The stiffeners of the first and second PCAPs 148 and 149 have barbs(for example, see barbs 158–161) that are used to anchor the PCAPs 148and 149 in place in insulative portion 147 in the same way that thebarbs are used to anchor the PCAPs 104 and 105 in place in theinsulative housing 103 of female connector 102 as described above.

FIG. 27 is a perspective view of first PCAP 148.

FIG. 28 is an expanded cross-sectional perspective view of first PCAP148 taken along sectional line D—D of FIG. 27. In the same way that theprinted circuits in the female connector have longer strip-shaped groundconductors and shorter intervening strip-shaped signal conductors, sotoo does first PCAP 148 have longer strip-shaped ground conductors 162and 163 and intervening shorter strip-shaped signal conductors 164 and165. A ground plane 166 is disposed on the back side of printed circuit150 and this ground plane is connected to the longer strip-shaped groundconductors by conductive through holes. Two such conductive throughholes are indicated by reference numerals 167 and 168. A solder masklayer on the backside of first printed circuit 150 separates the groundplane 166 from the stiffener 151. The bottom portion 169 of the frontside of first printed circuit 150 is not covered by solder mask so thatthe contact beams of the first PCAP 104 of female connector 102 canengage and make contact with the conductors in this area when the maleand female connectors are mated. A solder mask layer 170 is disposed onthe upper part of the front side of first printed circuit 150 withdefined openings where the solder tails are soldered or brazed to theprinted circuit 150.

FIG. 29 is an exploded view of first PCAP 148 showing row 144 of soldertails, first printed circuit 150 and stiffener 151.

FIG. 30 is an expanded cross-sectional view of a portion of firstprinted circuit 150. Note that the longer strip-shaped ground conductors162 and 163 are coupled by conductive through holes to the ground plane166 on the back side of first printed circuit 150.

FIG. 31 is an expanded view of the portion of first printed circuit 150in box 171 of FIG. 30.

FIG. 32 is a perspective cross-sectional view of first printed circuit150 with the dielectric and solder mask layers not shown so that theconductive portions of the structure can be more easily seen.

FIG. 33 is an expanded cross-sectional view of male connector 101 takenalong line C—C in FIG. 24.

FIG. 34 is an expanded view of the portion of male connector 101 in box172 of FIG. 33. Solder tail 155 is soldered to or is brazed to secondprinted circuit 153. Solder tail 155 is coupled to a longer strip-shapedground conductor 173, so solder tail 155 is electrically coupled by aconductive through hole 174 to the ground plane 175 on the back side ofsecond printed circuit 153. A solder mask layer 176 separates groundplane 175 from metal stiffener 154. Stiffener 154 is a piece of rigidmetal that is stamped out of a larger sheet of rigid metal. AlthoughFIG. 34 shows a cross-section of a ground conductor and associatedsolder tail where the solder tail is electrically coupled to the groundplane, there are other signal conductors and associated solder tailsthat are not coupled to the ground plane.

FIG. 35 is a cross-sectional diagram showing male connector 101 andfemale connector 102 before mating. The contact beams of the femaleportion 102 are not flexed outward.

FIG. 36 is a cross-sectional diagram showing male connector 101 andfemale connector 102 after mating. A portion of male connector 101 isdisposed in the male connector receiving slot (MCRS) 116. The contactbeams of first PCAP 104 of female connector 102 press to the right andmake electrical contact with corresponding ones of the strip-shapedconductors of first PCAP 148 of male connector 101. The contact beams ofsecond PCAP 105 of female connector 102 press to the left and makeelectrical contact with corresponding ones of the strip-shapedconductors of second PCAP 149 of male connector 101. The contact beamsof the female connector therefore press on both sides of the maleconnector.

FIG. 37 is a simplified cross-sectional diagram showing strip-likeconductors 200 and 201 and contact beam 202 that cooperate to form asignal path through the connector assembly 100. The printed circuits 111and 153 overlap one another by approximately 2.0 millimeters. Thecontact beam length is approximately 3.0 millimeters. The separationbetween to two printed circuits 111 and 153 is approximately 0.2millimeters. Note that the shorter strip-shaped signal conductors stopshort of the ends of the printed circuits 111 and 153 by the amount ofprinted circuit overlap (2.0 millimeters in this example).

FIG. 38 is a simplified cross-sectional diagram showing longerstrip-like ground conductors 203 and 204, ground planes 175 and 125, andcontact beam 205 that cooperate to form a shielding ground planestructure through and across the connector assembly 100. The printedcircuits 111 and 153 overlap one another by the same dimensions in FIG.38 as in FIG. 37. Note that the longer strip-shaped ground conductorsextend all the way to the ends of the printed circuits 111 and 153 sothat grounded conductors will cover a side of the contact beam 202 ofFIG. 37 used to conduct a signal. Also note that the longer strip-shapedground conductors are coupled by conductive through holes 206–209 toground planes 175 and 125. The grounded conductive structures of FIG. 38form a sort of shield around a tubular volume through which differentialpairs of signals conductors extend.

FIG. 39 is a graph showing electrical characteristics of novel connectorassembly 100. At a signal rate of 22 gigahertz, the insertion loss isbetter than −3 dB (the signal propagation has degraded by less than 3dB), and the return loss is better than −10 dB (the magnitude ofreflections is less than −10 dB). Where standards require both aninsertion loss of better than −3 dB and a return loss of better than −10dB, the connector assembly 100 is said to be able to handle signals upto 22 gigahertz.

FIG. 40 is a perspective view of an alternative embodiment where theprinted circuit boards 300 and 301 are not disposed parallel to oneanother as in the case of a stacking connector assembly, but rather aredisposed at right angles with respect to one another. The connectorassembly is called a “vertical mating” connector. Male connector 302 issurface mounted to printed circuit board 300. Female connector 303 ismounted to printed circuit board 301.

FIG. 41 is a cross-sectional diagram of the connector assembly of FIG.40. Female connector 303 has an identical construction to the femaleconnector 102 described above. Male connector 302, however, has twoinsulative portions 304 and 305 rather than just one insulative portionas in the example of FIG. 25. In a first assembly step, the first andsecond PCAPs are assembled and inserted into receiving slits ininsulative portion 304. The upper ends of the PCAPs extend upward fromthe top of the insulative portion 304. Rather than the printed circuitsof the PCAPs being rigid printed circuit, the printed circuits of thePCAPs of FIG. 41 are flexible printed circuits. The surface mountattachment structures at this point are not bent, but rather areattached to the printed circuits but extend straight in the plane of theprinted circuits. The printed circuits are then bent ninety degrees tothe right. The bent ends of the printed circuits are slid into receivingslits in the second insulative portion 305. The first and secondinsulative portions 304 and 305 snap together as illustrated incross-section in FIG. 41. The ends of the surface mount attachmentstructures are then bent so that they appear as shown in cross-sectionin FIG. 41. The resulting ninety degree male connector 302 is solderedto printed circuit board 300. Female connector 303 is soldered toprinted circuit board 301. The male and female connectors are thenbrought together and mated to form the structure illustrated in FIG. 41.

The novel connector structure having a female connector with two printedcircuits and opposing sets of contact beams can take multiple differentforms. FIG. 42 shows the stacking embodiment described above inconnection with FIGS. 11–39. FIG. 43 shows the vertical matingembodiment of FIGS. 40 and 41. FIG. 44 shows a horizontal matingembodiment. Both the male and female connectors 400 and 401 are madeusing flexible printed circuits as described in connection with thevertical mating embodiment such that both the female connector and themale connector are ninety degree connectors. The first and secondprinted circuit boards 402 and 403 are disposed in the same approximateplane. FIG. 45 illustrates an embodiment involving an extension portion500 that has two male ends 501 and 502. Each male end has the formillustrated above in FIG. 25. A first female connector 503 of the typeillustrated in FIG. 13 is soldered to a first printed circuit board 504.A second female connector 505 is soldered to a second printed circuitboard 506. Signal traces in the first printed circuit board 504 arecoupled to corresponding signal traces in the second printed circuitboard 506 through the assembly involving the two female connectors 503and 505 and the male—male extension connector 500.

In another embodiment, a novel connector assembly includes femalesurface mount attachment connector and a male surface mount attachmentconnector. The female connector has a PCAP and a contact beam portion,wherein the PCAP and the contact beam portion are coupled to anddisposed in an insulative housing such that contact beams of the PCAPface opposing contact beams of the contact beam portion. The contactbeam portion does not include a printed circuit but rather is a set ofstamped metal members, where one end of each member is a contact beamthat faces the PCAP and where the other end of each member is a surfacemount attachment feature.

In one embodiment, one (or both) of the PCAPs of a connector assembly(for example, the connector assembly of FIG. 11) includes contact beamsand a printed circuit. The printed circuit includes a ground plane asdescribed above in connection with FIG. 13, but the PCAP furtherincludes circuitry disposed on the printed circuit. In the diagram ofFIG. 13, the circuitry is surface mounted to the outwardly facingsurface of printed circuit 111. The ground plane is a ground planeinside the printed circuit 111, whereas the circuitry is soldered totraces or solder pads on the outwardly facing printed circuit boardsurface. The contact beams are soldered to the inwardly facing surfaceof the printed circuit. The circuitry may, for example, include: 1)memory integrated circuits, 2) discrete components such as capacitors,inductors, and resistors, 3) communication circuitry such as SERDESintegrated circuits, 4) impedance matching integrated circuits, theimpedance of which can be controlled to facilitate the communication ofelectrical signals through the connector assembly. The circuitry can bedisposed in this way on any one of the printed circuits appearing in theconnector assembly of FIG. 11, including printed circuits in the maleconnector.

Although the present invention has been described in connection withcertain specific embodiments for instructional purposes, the presentinvention is not limited thereto. Accordingly, various modifications,adaptations, and combinations of various features of the describedembodiments can be practiced without departing from the scope of theinvention as set forth in the claims.

1. A connector assembly comprising: a female connector comprising: aninsulative housing portion; a first printed circuit assembly portion(PCAP) comprising a first printed circuit (PC) and a first plurality ofcontact beams that are attached to the first printed circuit, the firstprinted circuit comprising a first ground plane; and a second printedcircuit assembly portion (PCAP) comprising a second printed circuit (PC)and a second plurality of contact beams that are attached to the secondprinted circuit, the second printed circuit comprising a second groundplane, wherein the first and second PCAPs are coupled to the insulativehousing such that a male connector receiving slot (MCRS) is formedbetween the first set of contact beams of the first PCAP and the secondplurality of contact beams of the second PCAP; and a male connectorhaving a first side and a second side, a first plurality of conductorsbeing disposed on the first side, a second plurality of conductors beingdisposed on the second side, wherein when a portion of the maleconnector is inserted into the MCRS of the female connector the firstplurality of contact beams press on the first side of male connector andthe second plurality of contact beams press on the second side of themale connector.
 2. The connector assembly of claim 1, wherein the firstPCAP includes a first plurality of surface mount attachment features,wherein the second PCAP includes a second plurality of surface mountattachment features, the first and second pluralities of surface mountattachment features being adapted for surface mount attaching the femaleconnector to a first printed circuit board.
 3. The connector assembly ofclaim 2, wherein some of the first plurality of contact beams are groundcontact beams, wherein others of the first plurality of contact beamsare signal contact beams, wherein the ground contact beams of the firstplurality of contact beams are electrically coupled to the first groundplane, and wherein each of the signal contact beams of the firstplurality of contact beams is not electrically coupled to the firstground plane and is not electrically coupled to any other one of thefirst plurality of contact beams, and wherein some of the secondplurality of contact beams are ground contact beams, wherein others ofthe second plurality of contact beams are signal contact beams, whereinthe ground contact beams of the second plurality of contact beams areelectrically coupled to the second ground plane, and wherein each of thesignal contact beams of the second plurality of contact beams is notelectrically coupled to the second ground plane and is not electricallycoupled to any of other one of the second plurality of contact beams. 4.The connector assembly of claim 2, wherein the first PCAP furthercomprises a first stamped metal stiffener, and wherein the second PCAPfurther comprises a second stamped metal stiffener.
 5. The connectorassembly of claim 2, wherein the male connector comprises: a firstprinted circuit assembly portion (PCAP) comprising a plurality ofconductors and a ground plane, the plurality of conductors of the firstPCAP being the first plurality of conductors of the male connector,wherein when the portion of the male connector is inserted into the MCRSof the female connector each of the first plurality of conductors of thefirst PCAP of the male connector makes electrical contact with acorresponding one of the first plurality of contact beams of the firstPCAP of the female connector; and a second printed circuit assemblyportion (PCAP) comprising a plurality of conductors and a ground plane,the plurality of conductors of the second PCAP being the secondplurality of conductors of the male connector, wherein when the portionof the male connector is inserted into the MCRS of the female connectoreach of the second plurality of conductors of the second PCAP of themale connector makes electrical contact with a corresponding one of thesecond plurality of contact beams of the second PCAP of the femaleconnector.
 6. The connector assembly of claim 5, wherein the first PCAPof the male connector includes a first plurality of surface mountattachment features, wherein the second PCAP of the male connectorincludes a second plurality of surface mount attachment features, thefirst and second pluralities of surface mount attachment features of themale connector being adapted for surface mount attaching the maleconnector to a second printed circuit board.
 7. The connector assemblyof claim 6, wherein a conductive path is established from one of thefirst plurality of surface mount attachment features of the femaleconnector to one of the first plurality of surface mount attachmentfeatures of the male connector, the conductive path having acharacteristic impedance that varies by less than plus or minus tenpercent.
 8. The connector assembly of claim 6, wherein a conductive pathis established from one of the first plurality of surface mountattachment features of the female connector to one of the firstplurality of surface mount attachment features of the male connector,wherein at a signal rate of 20 gigahertz down the conductive path thereis better than −3 dB signal loss and a better than −10 dB return loss.9. The connector assembly of claim 5, wherein the plurality ofconductors and the ground plane of the first PCAP of the male connectorare parts of a first printed circuit (PC) of the male connector, whereinthe plurality of conductors and the ground plane of the second PCAP ofthe male connector are parts of a second printed circuit (PC) of themale connector.
 10. A connector assembly comprising: a female surfacemount connector comprising: an insulative housing portion; a firstprinted circuit assembly portion (PCAP) comprising a first printedcircuit (PC) and a first plurality of contact beams that are attached tothe first PC, the first PC comprising a first ground plane; and a secondprinted circuit assembly portion (PCAP) comprising a second printedcircuit (PC) and a second plurality of contact beams that are attachedto the second PC, the second PC comprising a second ground plane,wherein the first and second PCAPs are coupled to the insulative housingsuch that a male connector receiving slot (MCRS) is formed between thefirst set of contact beams of the first PCAP and the second plurality ofcontact beams of the second PCAP; and a male surface mount connectorcomprising: an insulative portion; a first printed circuit assemblyportion (PCAP) comprising a first printed circuit (PC), the first PCcomprising a first plurality of conductors and a first ground plane; anda second printed circuit assembly portion (PCAP) comprising a secondprinted circuit (PC), the second PC comprising a second plurality ofconductors a second ground plane, wherein when a portion of the maleconnector is inserted into the MCRS of the female connector each of thefirst plurality of contact beams of the first PCAP of the femaleconnector makes electrical contact with a corresponding one of the firstplurality of conductors of the first PCAP of the male connector, whereinwhen the portion of the male connector is inserted into the MCRS of thefemale connector each of the second plurality of contact beams of thesecond PCAP of the female connector makes electrical contact with acorresponding one of the second plurality of conductors of the secondPCAP of the male connector, wherein when the portion of the maleconnector is inserted into the MCRS of the female connector the firstground plane of the female connector is electrically coupled to thefirst ground plane of the male connector, wherein when the portion ofthe male connector is inserted into the MCRS of the female connector thesecond ground plane of the female connector is electrically coupled tothe second ground plane of the male connector, and wherein when theportion of the male connector is inserted into the MCRS of the femaleconnector the portion of the male connector is pressed between the firstplurality of contact beams and the second plurality of contact beams.11. The connector assembly of claim 10, wherein the first PCAP of thefemale connector further comprises a surface mount attachment feature,wherein the first PCAP of the male connector further comprises a surfacemount attachment feature, wherein when the portion of the male connectoris inserted into the MCRS of the female connector a conductive path isestablished from the surface mount attachment feature of the first PCAPof the female connector through the connector assembly and to thesurface mount attachment feature of the first PCAP of the maleconnector, wherein at a signal rate of 20 gigahertz down the conductivepath there is better than −3 dB signal loss and a better than −10 dBreturn loss.
 12. The connector assembly of claim 11, wherein a pluralityof the first plurality of contact beams of the female connector iselectrically coupled to the first ground plane of the first PC of thefemale connector, and wherein a plurality of the second plurality ofcontact beams of the female connector is electrically coupled to thesecond ground plane of the second PC of the female connector.
 13. Theconnector assembly of claim 11, wherein the first PC of the femaleconnector includes conductive through holes that electrically couple thefirst ground plane to ones of the first plurality of contact beams ofthe female connector, and wherein the second PC of the female connectorincludes conductive through holes that electrically couple the secondground plane to ones of the second plurality of contact beams of thefemale connector.
 14. The connector assembly of claim 11, wherein thefirst PC of the female connector further comprises a first plurality ofconductors, wherein each of the first plurality of contact beams of thefemale connector is coupled to a corresponding one of the firstplurality of conductors of the first PC of the female connector, whereinthe second PC of the female connector further comprises a secondplurality of conductors, wherein each of the second plurality of contactbeams of the female connector is coupled to a corresponding one of thesecond plurality of conductors of the second PC of the female connector.15. The connector assembly of claim 11, wherein the first PCAP of thefemale connector further comprises a stiffener, wherein the second PCAPof the female connector further comprises a stiffener, wherein the firstPCAP of the male connector further comprises a stiffener, and whereinthe second PCAP of the male connector further comprises a stiffener. 16.The connector assembly of claim 11, wherein every third one of the firstplurality of contact beams of the female connector is coupled to thefirst ground plane of the female connector, and wherein every third oneof the second plurality of contact beams of the female connector iscoupled to the second ground plane of the female connector.
 17. A methodcomprising: providing a pair of printed circuits (PCs) in a femalesurface mount connector, wherein each of the PCs includes a ground planeand a plurality of conductors; providing a first plurality of contactbeams, wherein each of the first plurality of contact beams is connectedto a corresponding one of the conductors of a first one of the pair ofPCs; and providing a second plurality of contact beams, wherein each ofthe second plurality of contact beams is connected to a correspondingone of the conductors of a second one of the pair of PCs, wherein thefirst plurality of contact beams are flexible in a direction away fromthe second plurality of contact beams, and wherein the second pluralityof contact beams are flexible in a direction away from the firstplurality of contact beams.
 18. The method of claim 17, furthercomprising: providing a male surface mount connector that isdisengageably connectable to the female surface mount connector suchthat a conductive path is established from a surface mount feature onthe female connector, through one of the contact beams of the femaleconnector and to a surface mount feature on the male connector, whereinat a signal rate of 20 gigahertz down the conductive path there isbetter than −3 dB signal loss and a better than −10 dB return loss. 19.The method of claim 18, further comprising: coupling every third one ofthe first plurality of contact beams to the ground plane of the firstone of the pair of PCs; and coupling every third one of the secondplurality of contact beams to the ground plane of the second one of thepair of PCs.
 20. The method of claim 19, wherein when the male surfacemount connector is disengageably connected to the female surface mountconnector a portion of the male surface mount connector is disposedbetween the first plurality of contact beams and the second plurality ofcontact beams such that the first plurality of contact beams presses onone side of the male surface mount connector and the second plurality ofcontact beams presses on a side of the male surface mount connector thatis opposite said one side.